1. Field of the Invention
This invention relates in general to certain new and useful improvements in track assemblies for moving flexible enclosure covers over an area to be enclosed and more particularly to an assembly of the type stated which allows for collection of debris in the tracks and which also permits adjustable positioning of the leading edge of the cover with respect to the tracks.
2. Brief Description of the Related Art
In recent years, automatic swimming pool cover system have become quite popular with both residential pool owners and commercial swimming pool operators. These automatic pool cover systems are preferred over conventional manually movable covers inasmuch as they are effective in precluding the collection of debris in the swimming pool and reduce the frequency and amount of pool maintenance which would otherwise be required. In addition, they provide a significant safety factor in that the construction is such that one or more individuals may literally walk on the pool cover while it is extended over a swimming pool body of water. Further, these swimming pool covers are effective in that they reduce heat loss and further can actually increase water temperature through solar effects.
The commercially available swimming pool cover systems usually employ a powered reel upon which a flexible swimming pool cover is rolled. A pair of tracks are mounted on opposite sides of the swimming pool and the leading edge of the cover is connected to a motor driving the reel through a cable arrangement. U.S. Pat. No. 5,349,707, dated Sep. 27, 1994, to Harry J. Last, and U.S. Pat. No. 4,393,798, dated Jul. 10, 1990, to Harry J. Last, are representative of pool covers of this type. Alternate types of assemblies are shown in U.S. Pat. No. 4,464,801, dated Aug. 14, 1984, to Joe H. Lamb, and U.S. Pat. No. 4,466,144, dated Aug. 21, 1984, to Joe H. Lamb.
When the swimming pool cover is to be advanced to a position where it closes off the swimming pool, the cable arrangement will pull the leading edge of the cover until the cover fully extends over the swimming pool. The sides of the cover are mounted on the cables which move within the tracks mounted at the opposite sides of the swimming pool. When sliders are used, the cover is secured to the sliders which are, in turn, secured to the cables. In like manner, when it is desired to remove the swimming pool cover, the motor causes the reel to rotate in a reverse direction and thereby wind the cover onto the reel. Otherwise, a pair of motors may be employed for this purpose.
The tracks which are used to receive the sliders on the sides of the swimming pool covers usually contain a track receiving channel with a slit on a surface of the track leading into the channel. The slider contains a strip which extends through this elongate relatively narrow slit into the channel and on its inner end has a circular tube or so-called "guide" which rides within the slider mechanism receiving channel in the track. In this way, the slider is precluded from moving outwardly from the track and allows for sliding movement of the cover along the track.
Track constructions of the foregoing type are illustrated and described in U.S. Pat. No. 3,060,455, dated Oct. 30, 1962, to Joe H. Lamb, U.S. Pat. No. 3,979,782, dated Sep. 14, 1976, to Joe H. Lamb, and U.S. Pat. No. 4,939,798, dated Jul. 10, 1990, to Harry J. Last.
However, debris, such as twigs, leaves, dirt and the like, readily collects within this track receiving channel, and which will ultimately materially interfere with the movement of the slider within the channel. In fact, in many cases where the swimming pools are located near a large number of trees, and particularly pine trees, the collected debris including pine needles and cone fragments can actually cause the slider to literally jam within the track. This requires the pool owner or an attendant to literally get on his or her hands and knees and attempt to manually clean out the track to free the slider mechanism.
Another one of the problems associated with the tracks normally used with the automatic pool cover systems is the fact that there is essentially no means to enable a lubricant to remain within the track as the slider moves within the cable receiving channel. In these conventional slider track assemblies, the slider tends to literally push any lubricant out of an end of the cable receiving channel. Accordingly, the pool owner or a pool attendant or other maintenance personnel must periodically introduce a lubricant into the slide receiving channel.
There have also been several attempts to mount a track on the side of and flush with the upper surface of a deck. This is oftentimes desirable when obstacles may exist on the deck at or adjacent to the edge of the swimming pool, or otherwise, where surface mounted tracks adjacent to pool might otherwise interfere with pool side activities or the like. These so-called "flush mounted tracks" are usually located within a groove formed in the surface of the deck adjacent to a side of the pool.
In the flush mounted track systems, the flexible cover must be angulated at the edge of the track for extending into the cable receiving channel and for securement to the cable in that channel. This type of construction thereby causes extensive wear. very rapidly on the cover itself. For this purpose, sliders are preferably employed. However, and here again, when the cover is secured to the slider, a substantial torque is imposed on the slider, and this torque imposes a bending force on the track.
Further, inasmuch as a slider must extend upwardly from a flush mounted track and is angulated with respect to a horizontal plane, additional forces are imposed on the track system. Typically, in this construction, sliders extend outwardly from the tracks and are connected to leading edges of the swimming pool cover. As such, the sliders are forced upwardly and downwardly as the cover is forced upwardly and downwardly in a vertical plane. This vertical shifting movement introduces a twisting moment on the leading edges of the pool cover and is imparted to the cable securing tube of the slider, or so-called "slider tube", which operates in the bulbous portion of the track, as the leading edge of the pool is raised and lowered. There has been some need for a means to enable a sideways adjustment in the horizontal plane and to provide for an adjustable positioning of the slider mechanism relative to the track.
In many commercial swimming pools, the swimming pool covers must traverse a fairly substantial width, and moreover are unsupported in this dimension across the width of the swimming pool. The leading edge of the swimming pool cover, by virtue of its weight over this large distance, can impose a substantial force on the track assemblies, and moreover, cause a bending moment on the track assemblies. In order to support this additional load, roller assemblies have been proposed. However, these roller assemblies are generally not effective for their intended purpose.
In addition, and in an effort to support the load at the leading edge of a swimming pool cover, so-called "floating leading edges" have been employed. However, these edges again impart a twisting moment to either the cable or otherwise to the slider, and hence, may cause premature wear to the sliders and to the tracks.
Additional swimming pool cover assemblies are shown in the prior art as, for example, in U.S. Pat. No. 5,067,184, dated Nov. 26, 1991, to Harry J. Last, and also in U.S. Pat. No. 4,466,143, dated Aug. 21, 1984, to Joe Lamb, and in U.S. Pat. No. 3,979,782, dated Sep. 14, 1976, to Joe H. Lamb. Cover systems are also shown in United Kingdom Patent Application No. 2,072,006A, and Canadian Patent No. 1,046,706. However, none of these slider track arrangements solve the specific problems identified herein.